KR102113229B1 - Motor - Google Patents

Abstract

According to the present invention, a motor includes: a stator; and a rotor disposed inside or outside the stator to be rotatable. The rotor includes: a plurality of rotor core segments arranged at a distance from each other inside or outside the stator in a circumferential direction of the rotor to form a plurality of permanent magnet placement slots; a plurality of permanent magnets inserted into the plurality of permanent magnet placement slots respectively to be arranged alternately with the plurality of rotor core segments in a circumferential direction of the rotor; a rotor frame fixing the plurality of permanent magnets and the plurality of rotor core segments to integrate the plurality of permanent magnets and the plurality of rotor core segments; and an outer ring formed of a nonmagnetic material to surround an outer end of the plurality of permanent magnets and an outer end of the plurality of rotor core segments. Therefore, the motor is capable of considerably improving the structural strength of a rotor while preventing a deterioration in performance and an increase in size.

Description

Motor {MOTOR}

The present invention relates to a motor.

The motor refers to a device that provides a rotating shaft with a rotational force generated by electromagnetic interaction between the stator and the rotor. In order to generate the rotational force, a coil is wound on the stator, and when a current is applied to the coil, the rotor rotates. The motor can be used in various fields such as washing machines, refrigerators, compressors, and vacuum cleaners. For example, the motor may be connected to the drum of the washing machine by a rotating shaft to realize rotation of the drum.

In general, a permanent magnet type motor may be classified into a surface mounted type and an interior permanent magnet according to the type of attachment of the permanent magnet. The surface-attached type refers to a form in which a permanent magnet is attached to the surface of the rotor core. The embedded type refers to a form in which a permanent magnet is embedded in the rotor core. Among the embedding type, the form in which the rotor core and the permanent magnet are erected along a height direction parallel to the axial direction of the rotating shaft may be sub-classified as a spoke type.

The spoke type motor has an advantage of improving the efficiency and performance of the rotor through the concentration effect of the magnetic flux using the rotor core. However, when the rotational speed of the rotating shaft generated in the spoke-type motor is excessively fast, there is a fear that the structural strength of the rotor is lowered. For example, the rotating shaft of the motor installed in the washing machine rotates at a faster speed than other strokes during the dehydration stroke, and sometimes exceeds 1,200 rpm.

When the rotating shaft of the motor is excessively rotated, a strong centrifugal force acts on the rotor of the motor. In addition, due to the strong centrifugal force, a permanent magnet of the rotor or a rotor core may be broken in the radial direction of the rotor. In order to solve this problem, in Korean Patent Application Publication No. 10-2012-0110275 (2012.10.10. 2012), which is a prior patent document, the permanent magnet 140 and the rotor core 131 are disposed above and below as the first fastening member 152. And, a structure for disposing the rotor core 131 through the second fastening member 153 is disclosed.

When the rotating shaft of the motor rotates at a slow speed, the structure disclosed in the prior patent document uses the two fastening members 152 and 153 and the rotor housing 150 to remove the permanent magnet 140 and the rotor core 131. Can be prevented. However, since the first fastening member 152, the second fastening member 153, and the rotor housing 150 are composed of separate parts from each other, when the rotation axis of the motor rotates at a very high speed, due to a lack of physical coupling force between the parts The possibility of breakage is very high.

In addition, since the first fastening member 152 is disposed above and below the permanent magnet 140 and the rotor core 131, it causes the motor to increase in size.

In addition, in order to manufacture the structure of the prior patent document, the rotor housing 150, the rotor core 131, the permanent magnet 140, the first fastening member 152 and the second fastening member 153, etc. Therefore, it should be assembled sequentially. In this respect, the productivity is very low, and particularly, as the number of fastening members increases, it is disadvantageous for mass production.

As described above, a person skilled in the art (one of ordinary skill in the art) tries to restrain a permanent magnet or a rotor core by introducing structures such as fastening members in addition to the original parts constituting the rotor. However, it is difficult to improve the structural strength without increasing the size or performance of the rotor that rotates at high speed only by simple introduction of structures such as fastening members.

When the structural strength of the rotor is to be reinforced by simple introduction of structures such as fastening members, a hole must be formed in the rotor core segment to insert the fastening member, and the fastening process between fastening members must be performed. When the size of the fastening member is increased in order to increase the rigidity of the fastening member itself, a reduction in the size of the rotor core segment is inevitable, resulting in a decrease in the performance of the motor and an increase in the motor size. This is contrary to the tendency of technology development in this technical field, where the technology is being developed in the direction of improving the performance of the motor, but gradually reducing the size of the motor. Accordingly, the present invention is to propose a structure that can improve the structural strength of the motor without causing a reduction in performance or size of the motor.

When the connection strength between the fastening members is insufficient, a strong centrifugal force acting on the rotor during high-speed operation of the motor causes damage to the rotor. In particular, considering that the necessity of a motor that operates at a high speed such as a washing machine or a vacuum cleaner is continuously increasing, it is insufficient to secure the structural strength only at a low speed operation. Accordingly, the present invention is to provide a motor having a structure capable of preventing the permanent magnet and the rotor core segment from being damaged in the radial direction due to strong centrifugal force acting on the rotor even when the motor is operated at high speed. In addition, the present invention is to propose a structure that can solve the problem of damage to the motor caused by the lack of physical coupling between the individual parts.

The present invention is to propose a structure that can improve the productivity of the motor through the integration of parts, beyond the level of a person skilled in the art to improve the structural strength of the rotor through the introduction of fastening members.

Furthermore, the present invention is to provide a configuration in which a rotor core segment and a permanent magnet are stably mounted at a fixed position in the rotor frame in the process of manufacturing the motor, and can maintain a tightly coupled state.

In order to achieve such an object of the present invention, a motor according to an embodiment of the present invention includes a stator and a rotor, and the rotor is formed to surround the outer ends of the plurality of rotor core segments and the outer ends of the plurality of permanent magnets. It includes an outer ring (outer ring). The outer ring is formed of a non-magnetic material. While the outer ring constrains the plurality of rotor core segments and the plurality of permanent magnets in the radial direction, it does not cause performance degradation due to the size reduction of the rotor core segment in that it does not penetrate the rotor core segment. In addition, since the outer ring can be pressed into the outer ends of the plurality of rotor core segments and the outer ends of the plurality of permanent magnets, separate fastening is unnecessary.

In particular, the outer ring can be integrated with a plurality of rotor core segments and a plurality of permanent magnets by a rotor frame. When a plurality of rotor core segments, a plurality of permanent magnets, and an outer ring are integrated, the rotor can have stronger structural strength.

The rotor may be an inner rotor rotatably disposed inside the stator or an outer rotor rotatably disposed outside the stator.

The plurality of rotor core segments are arranged to be spaced apart from each other along the circumferential direction of the rotor inside or outside the stator to form a plurality of permanent magnet placement slots.

The plurality of permanent magnets are inserted in each of the plurality of permanent magnet placement slots so as to be alternately arranged one by one with the plurality of rotor core segments along the circumferential direction of the rotor.

The rotor frame fixes the plurality of rotor core segments and the plurality of permanent magnets to integrate the plurality of rotor core segments and the plurality of permanent magnets. Furthermore, the rotor frame fixes the plurality of rotor core segments, the plurality of permanent magnets, and the outer ring so as to integrate the plurality of rotor core segments, the plurality of permanent magnets, and the outer ring.

The outer ring has a specific permeability of 1 to 1.05.

The thickness of the outer ring based on the radial direction of the rotor frame is 0.5 mm to 3.5 mm.

The rotor frame is connected to a rotating shaft passing through the stator, and a ratio (h /) of the length (h) of the outer ring and the length (A) of the plurality of rotor core segments in a direction parallel to the axial direction of the rotating shaft. A) is from 0.3 to 1.5. More preferably, the ratio (h / A) of the length (h) of the outer ring length and the length (A) of the plurality of rotor core segments in a direction parallel to the axial direction of the rotation axis is 0.66 to 1.

The outer ring may be formed by rolling a belt having a first end and a second end on the outer ends of the plurality of rotor core segments and the outer ends of the plurality of permanent magnets.

The first end and the second end are joined to each other by welding. A welding portion is formed at a connection portion between the first end and the second end.

Each of the first end and the second end includes: a circumferential protrusion protruding toward the opposite end in the circumferential direction of the outer ring; And a cross-direction protruding part protruding from each circumferential protruding part in a direction crossing the circumferential direction.

The crossing projections of the first stage and the crossing projections of the second stage are staggered to each other.

The outer ring is in close contact with the outer ends of the plurality of rotor core segments and the outer ends of the plurality of permanent magnets, and the rotor frame is formed to surround the outer ring.

Each of the plurality of rotor core segments may include a body formed to face the permanent magnet in a circumferential direction of the rotor; A head protruding from both sides along the circumferential direction of the rotor at the inner end of the body; And protrusions protruding from the outer end of the body and extending in two directions toward directions away from each other to form a rotor core slot.

Each of the plurality of permanent magnet placement slots is formed by the body, the head and the projection of two rotor core segments disposed on both sides of the one permanent magnet based on any one of the plurality of permanent magnets.

On the contrary, the rotor frame is in close contact with the outer ends of the plurality of rotor core segments and the outer ends of the plurality of permanent magnets, and the outer ring may be formed to surround the rotor frame.

The plurality of rotor core segments, the plurality of permanent magnets and the outer ring are integrated with the rotor frame by insert injection.

The rotor frame is connected to a rotating shaft passing through an area enclosed by the stator, and the rotor frame is formed to cover the first end and the second end of the outer ring in a direction parallel to the axial direction of the rotating shaft.

The rotor frame is formed to cover the first and second ends of the plurality of rotor core segments, and the first and second ends of the plurality of permanent magnets in a direction parallel to the axial direction of the rotating shaft, and the rotor frame The rotor frame pin is inserted into a hole or a rotor core slot formed in each of the plurality of rotor core segments toward a direction parallel to the axial direction of the rotation axis; And a rotor frame hole formed at each position facing the rotor frame pin along a direction parallel to the axial direction of the rotation axis.

The rotor frame pin and the rotor frame hole are spaced apart from each other along a direction parallel to the axial direction of the rotation axis.

The rotor frame includes a rotating shaft connecting portion connected to the rotating shaft; A spoke formed radially around the rotating shaft connection; A first stage formed along the circumferential direction on the outer side of the spoke, and formed to cover the first stage of the plurality of rotor core segments and the first stage of the plurality of permanent magnets in a direction parallel to the axial direction of the rotating shaft. Base; It is arranged to face the first end base in a direction parallel to the axial direction of the rotating shaft, and the second end of the plurality of rotor core segments in a direction parallel to the axial direction of the rotating shaft, the second end of the plurality of permanent magnets And a second stage base formed to cover the stage.

The rotor frame includes an outer wall, and the outer wall is formed to surround the outer ends of the plurality of rotor core segments, the outer ends of the plurality of permanent magnets, and the outer ring in the radial direction of the rotor frame. It extends along a direction parallel to the axial direction of the rotating shaft to connect the first stage base and the second stage base.

The rotor frame includes an inner column, and the inner column extends along a direction parallel to the axial direction of the rotating shaft to connect the inner end of the first end base and the inner end of the second end cover to each other.

The inner pillar is provided in plural, and the plurality of inner pillars are spaced apart from each other along the inner end of the first end base and the inner end of the second end cover.

An opening is formed between the two inner pillars, through which the inner end of the rotor core segment is exposed. The plurality of permanent magnets are covered by a plurality of the inner columns.

A permanent magnet fixing jig hole is formed at a boundary between the inner column and the first end base or between the inner column and the second end base, and the permanent magnet is visually exposed through the permanent magnet fixing jig hole.

Each of the rotor core segments includes a hole formed by laminating a sheet of electrical steel sheets and formed along a direction parallel to the axial direction of the rotating shaft; A rotor core slot formed at an outer end of the rotor core segment along a direction parallel to the axial direction of the rotating shaft; And a protruding mac that protrudes from one surface of each electric steel plate and is recessed from the other surface of the same position.

The circumference formed by the outer ends of the plurality of rotor core segments and the outer ends of the plurality of permanent magnets is interviewed along the circumferential direction with the inner circumferential surface of the outer ring.

According to the present invention having the above configuration, the performance of the motor is not reduced or the size is not increased through the introduction of an outer ring formed to surround a plurality of rotor core segments and a plurality of permanent magnets without relying on a plurality of fastening members. Also, the structural strength of the rotor can be greatly improved.

In particular, the outer ring can be integrated with a plurality of rotor core segments and a plurality of permanent magnets by a rotor frame. As components constituting the rotor are integrated, structural strength is secured to prevent damage to the rotor even when the motor is operated at high speed. Furthermore, the integration of parts constituting the rotor can fundamentally solve the problem of rotor damage due to the lack of physical coupling between individual parts.

Since the outer ring may be press-fitted to the outer ends of the plurality of rotor core segments and the outer ends of the plurality of permanent magnets, a separate fastening process is unnecessary in addition to press-fitting. Accordingly, the outer ring does not cause a decrease in productivity of the rotor. In particular, when the rotor is manufactured by insert injection, the productivity of the rotor may be further improved.

In addition, the present invention, the rotor frame pins and rotor frame holes, such as the rotor core segment and the permanent magnet in the manufacturing process of the rotor proposed a structure that can be stably mounted in place in the rotor frame, the parts of the completed rotor production It can maintain a tightly coupled state.

1 is a perspective view showing an embodiment of a motor related to the present invention.
FIG. 2 is a perspective view showing a state in which the rotor shown in FIG. 1 is cut along an axial direction.
3 is an exploded perspective view of the rotor.
4 is an enlarged partial perspective view of an IV portion shown in FIG. 3.
5 is a cross-sectional view of the portion V shown in FIG. 2.
Figure 6 is a perspective view showing the position and engagement of the rotor core segment, permanent magnet, outer ring, bushing before insert injection.
7A is a conceptual diagram before connecting the first end and the second end of the outer ring.
7B is a conceptual diagram after connecting the first end and the second end of the outer ring.
8 is a conceptual diagram showing the flow of magnetic flux to explain the effect of the present invention.

Hereinafter, the motor according to the present invention will be described in more detail with reference to the drawings.

In the present specification, the same or similar reference numerals are assigned to the same or similar configurations in different embodiments, and the description is replaced with the first description.

When an element is said to be "connected" or "connected" to another component, it is understood that other components may be directly connected to or connected to the other component, but there may be other components in between. It should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that no other component exists in the middle.

As used herein, a singular expression includes a plural expression unless the context clearly indicates otherwise.

1 is a perspective view showing an embodiment of a motor 100 related to the present invention.

The motor 100 includes a stator 110 and a rotor 120.

The stator 110 includes a stator core 111, an insulator 112, and a coil 113.

The stator core 111 is formed by stacking a plurality of sheets of electrical steel sheets (magnetic materials) along the axial direction of a rotating shaft coupled to the motor 100. The stator core 111 may be configured to surround the rotating shaft at a position spaced apart from the rotating shaft.

The insulator 112 is coupled to the stator core 111 on one side and the other side (up and down) along a direction parallel to the axial direction (not shown) of the rotating shaft (not shown). The insulator 112 is formed of an electrically insulating material. The insulator 112 has a stator fixing portion 112a and a tooth insulating portion 112b.

The stator fixing part 112a protrudes from the circumference of the insulator 112 toward the rotation axis. The stator fixing part 112a is formed in plurality. The plurality of stator fixing parts 112a are formed at positions spaced apart from each other along the circumference of the insulator 112. The stator fixing portion 112a is formed with a fastening member fixing hole that opens in a direction parallel to the axial direction of the rotating shaft. The position of the stator 110 is fixed as the fastening member is coupled to the fastening member fixing hole.

The tooth insulation portion 112b protrudes in the radial direction from the circumference of the insulator 112. The tooth insulation portion 112b insulates the coil 113 from a tooth connected to a yoke (not shown) by wrapping a tooth (not shown) around which the coil 113 is to be wound.

The coil 113 is wound on each tooth insulation 112b. In Fig. 1, the focus is shown. The coil 113 is applied with electric current. The motor 100 is operated by the current applied to the coil 113.

The rotor 120 is rotatably disposed inside or outside the stator 110. The inner and outer sides are determined to face the rotation axis disposed at the center in the radial direction of the rotor 120 or vice versa. The direction toward the rotation axis is inside, and the direction away from the rotation axis is outside. In FIG. 1, the rotor 120 shows an outer rotor 120 disposed outside the stator 110.

The rotor 120 includes a rotor frame 121. The rotor frame 121 may be referred to as a rotor housing. The rotor frame 121 is formed to surround the stator 110.

The rotor frame 121 includes a bushing coupling portion 121a, a spoke 121b, and an outer wall 121e.

The bushing coupling part 121a is formed to be coupled to a rotation axis passing through an area enclosed by the stator 110. The bushing coupling part 121a is formed at the center of the rotor frame 121 in the radial direction of the rotor 120. The center of the rotor frame 121 corresponds to a position facing the area enclosed by the stator 110.

The bushing coupling portion 122a is formed to be coupled to the bushing 122. The bushing 122 refers to a component connected to the rotating shaft. One end of the rotating shaft is coupled to the bushing 122, the other end can be directly connected to the object receiving the rotational force of the motor 100, such as a drum of the washing machine.

The bushing 122 may have a shape conforming to a hollow cylinder. The bushing 122 is provided with a thread 122a on the inner circumferential surface of the hollow so as to be coupled with the rotating shaft. The rotating shaft is directly inserted into the bushing 122. The rotating shaft and the rotor frame 121 are coupled to each other through the bushing 122.

A reinforcement rib 121a1 is formed around the bushing coupling portion 122a. The reinforcing ribs 121a1 are formed in plurality around the bushing coupling portion 122a, and the plurality of reinforcing ribs 121a1 protrude from the boundary between the bushing coupling portion 122a and the spoke 121b along a direction inclined to the rotation axis. do.

The spoke 121b extends in the radial direction from the bushing coupling portion 121a, or extends in an inclined direction at an acute angle with respect to the radial direction. The spokes 121b are provided in plural, and may be arranged around the bushing coupling parts 121a to face different directions. The spoke 121b is formed at a position covering one side or the other side of the stator 110 in a direction parallel to the axial direction of the rotating shaft. 1, it can be seen that the lower side of the stator 110 corresponds to the one side, and the upper side of the stator 110 corresponds to the other side. In this case, the spoke 121b is formed at a position covering the lower side of the stator 110 from below.

When a plurality of spokes 121b are formed in the radial direction around the bushing coupling portion 122a, a heat dissipation hole 121b1 is formed between the plurality of spokes 121b. Heat generated in the motor due to the operation of the motor may be discharged through the heat dissipation hole 121b1.

The outer wall 121e is formed to surround the stator 110 in the radial direction of the rotor 120. A plurality of rotor cores (or rotor core blocks, or rotor core segments) 123, which will be described later, and a plurality of permanent magnets 124 are installed inside the outer wall 121e.

For reference, in FIG. 1, the spoke 121b type motor 100 having the outer rotor 120 has been described, but the present invention necessarily includes the spoke 121b type motor 100 having the outer rotor 120. ) Is not limited to. For example, the present invention can be applied to an embedded motor having an inner rotor 120.

Components of the reference numerals not described in FIG. 1 will be described with reference to FIG. 2 showing only the rotor 120 except for the stator 110.

2 is a perspective view showing a state in which the rotor 120 shown in FIG. 1 is cut along an axial direction.

3 is an exploded perspective view of the rotor 120.

4 is an enlarged partial perspective view of a portion IV shown in FIG. 3.

The rotor 120 includes a plurality of rotor cores 123, a plurality of permanent magnets 124, and a rotor frame 121.

The plurality of rotor cores 123 are arranged to be spaced apart from each other along the circumferential direction of the rotor 120 on the outside of the stator 110 to form a permanent magnet placement slot MS. As the plurality of rotor cores 123 are arranged to be spaced apart from each other along the circumferential direction of the rotor 120, permanent magnet placement slots MS are formed between the two rotor cores 123. Permanent magnet placement slot (MS) is the side of the two rotor cores 123 disposed adjacent to the permanent magnet placement slot (MS), the head 123b of the two rotor cores 123, and the two rotor cores 123. It is an area enclosed by the projection 123c.

The plurality of rotor cores 123 is formed by stacking a plurality of sheets of electrical steel sheets (magnetic materials) along a direction parallel to the axial direction of the rotating shaft. The sheets of electrical steel sheets may have the same shape. However, at least one electric steel plate disposed at the bottom and at least one electric steel plate disposed at the top based on the stacking direction of the electric steel plates may be larger than other electric steel plates for supporting the permanent magnet 124.

If the rotor core 123 having a height of 39 mm is to be formed of a sheet of electric steel sheet having a thickness of 0.5 mm in a direction parallel to the axial direction of the rotation axis, 78 electrical steel plates may be stacked.

The rotor core 123 serves to concentrate the force of the permanent magnet 124. When the force of the permanent magnet 124 is concentrated on the rotor core 123, the performance of the motor 100 is dramatically increased. However, if a plurality of rotor cores 123 are connected to each other, the efficiency of the motor 100 is reduced. Therefore, in order to improve the efficiency of the motor 100, it is preferable that the plurality of rotor cores 123 are spaced apart from each other.

Referring to FIG. 3, each rotor core 123 includes a body 123a, a head 123b, a protrusion 123c, a hole 123d, a rotor core slot 123e, and a mac (123f) It is provided.

The body 123a corresponds to a portion occupying the largest volume of the rotor core 123. The body 123a is disposed to face the permanent magnet 124 in the circumferential direction of the rotor 120. Both sides of the body 123a are disposed to face the first working surface 124a of the permanent magnet 124, and are in surface contact with the first working surface 124a.

It can be understood that the plurality of rotor cores 123 are arranged along the side surface of the hollow cylinder. The portion located on the circumference corresponding to the inner diameter of the cylinder corresponds to the inner end of the body 123a. In addition, the outer end of the body 123a points to a portion where the projection 123c and the rotor core slot 123e, which will be described later, are formed. The inner end of the body 123a is disposed to face the stator 110 at a position spaced apart from the stator 110.

The width of the body 123a based on the circumferential direction of the rotor 120 may be formed to gradually widen from the inner end to the outer end of the body 123a. For example, the linear distance between both sides of the body 123a in the circumferential direction of the rotor 120 gradually increases as it goes from the inner end to the outer end of the body 123a.

When the virtual first circumference corresponding to the inner end of the rotor core 123 is compared with the virtual second circumference corresponding to the outer end of the rotor core 123, the second circumference is larger than the first circumference. If the first working surface 124a of the permanent magnet 124 extends in a direction parallel to the radial direction of the rotor 120, the area according to the difference between the first circumference and the second circumference is determined by the rotor core 123. Should be filled. To fill the area, the width of the body 123a based on the circumferential direction of the rotor 120 is formed to gradually widen from the inner end to the outer end. Accordingly, the plurality of rotor cores 123 and the plurality of permanent magnets 124 in the circumferential direction of the rotor 120 may be arranged without empty space.

The head 123b protrudes on both sides from the inner end of the body 123a toward the circumferential direction of the rotor 120. Two heads 123b are formed on one rotor core 123.

Two heads 123b are formed at a position facing the inner surface of the permanent magnet 124 based on one permanent magnet 124. These two heads 123b limit the movement of the permanent magnet 124 towards the axis of rotation. One of the two heads 123b corresponds to the head 123b of the rotor core 123 disposed on one side of the permanent magnet 124, and the other one is disposed on the other side of the permanent magnet 124 Corresponds to the head 123b of the core 123.

The two heads 123b are spaced apart from each other in the circumferential direction of the rotor 120. When the two heads 123b are connected to each other, the performance of the motor 100 is deteriorated. In order to maximize the performance of the motor 100, it is preferable that all the rotor cores 123 are spaced from each other, and all the permanent magnets 124 are spaced from each other. Therefore, it is preferable from the viewpoint of performance of the motor 100 that these two heads 123b are also spaced apart from each other.

The protrusion 123c protrudes from the outer end of the body 123a. The projections 123c extend in two directions toward directions away from each other to form the rotor core slot 123e. Two protrusions 123c are formed on one rotor core 123. The two projections 123c protrude toward the direction inclined to the radial direction of the rotor 120. Both sides of the protrusion 123c are disposed to face the second working surface 124b of the permanent magnet 124, and are in surface contact with the second working surface 124b.

Two projections 123c are formed at a position facing the outer surface of the permanent magnet 124 based on one permanent magnet 124. These two protrusions 123c constrain the permanent magnet 124 that is trying to move toward the direction away from the rotation axis by centrifugal force when the motor 100 is operated. One of the two projections 123c corresponds to the projection 123c of the rotor core 123 disposed on one side of the permanent magnet 124, and the other one is disposed on the other side of the permanent magnet 124 Corresponds to the projection 123c of the core 123.

The two projections 123c are spaced apart from each other in the circumferential direction of the rotor 120. When the two protrusions 123c are connected to each other, the performance of the motor 100 is deteriorated. In order to maximize the performance of the motor 100, it is preferable that all the rotor cores 123 are spaced from each other, and all the permanent magnets 124 are spaced from each other. Therefore, it is preferable from the viewpoint of performance of the motor 100 that these two projections 123c are also spaced apart from each other.

The hole 123d is formed in the body 123a. The hole 123d is opened toward a direction parallel to the axial direction of the rotation axis (up and down directions in Figs. 2 and 3). The hole 123d is formed between the inner end and the outer end of the body 123a in the radial direction of the rotor 120. Since the rotor core slot 123e is formed at the outer end of the body 123a, a hole is formed between the inner end of the body 123a and the rotor core slot 123e in the radial direction of the rotor 120.

The rotor core slot 123e is formed between two projections 123c in the circumferential direction of the rotor 120. The rotor core slot 123e may be understood as a shape recessed toward the body 123a between the two protrusions 123c based on the radial direction of the rotor 120. The circumference of the rotor core slot 123e is formed as a semicircle or a curved surface having a cross-section of a shape equivalent to a semicircle.

The hole 123d and the rotor core slot 123e are areas in which a mold pin is accommodated in an insert injection process, which will be described later, or a molten injection material is accommodated. For insert injection, a plurality of rotor cores 123 must be seated in the mold, and the plurality of rotor cores 123 must be fixed in place in the mold. In order to fix each rotor core 123 in place, a plurality of mold pins are formed in the mold. When the rotor core 123 is disposed in the mold such that each mold pin is inserted into the hole 123d or the rotor core slot 123e, fixing of each rotor core 123 is completed.

When a plurality of rotor cores 123 are seated at a fixed position in a mold by using a mold pin, and when the injection raw material in a molten state is introduced into the mold, the injection material is filled in the hole 123d and the rotor core slot 123e. Lose. When the insert injection is completed and the injection molded product is separated from the mold, a hole 123d and a rotor core slot 123e remain in the region where the mold pin was present. Further, a rotor frame pin 121g and a pin reinforcement rib 121h, which will be described later, are formed in the region filled with the injection material.

The mac 123f is formed for each sheet of electrical steel constituting each rotor core 123. The pulse 123f protrudes from one surface of each electric steel plate, and is formed in a protrusion shape that is recessed from the other surface of the same position as the protruding position. The pulse 123f may be formed in plural around the hole 123d, and the drawing shows a configuration in which three pulses 123f are formed on each electric steel sheet.

The mac 123f is a structure for stacking and stacking the sheets of electric steel sheets at positions corresponding to each other. When a plurality of electrical steel sheets are stacked in such a way that one protruding mac 123f of two electrical steel plates arranged to face each other is inserted into the other recessed mac 123f, constituting the rotor core 123 The electrical steel sheets can be aligned with each other along a direction parallel to the axial direction of the rotating shaft.

The plurality of rotor cores 123 are exposed inside the rotor 120 in the radial direction of the rotor 120. Here, the inside of the rotor 120 refers to a position where the bushing 122 is installed.

The outer ring 125, which will be described later, is in close contact with the outer end of the rotor core 123.

On the other hand, a plurality of permanent magnets 124 are arranged in a plurality of permanent magnets formed by the plurality of rotor cores 123 such that they are alternately arranged one by one with the plurality of rotor cores 123 along the circumferential direction of the rotor 120. It is inserted one by one into the slot MS. Since the plurality of permanent magnets 124 and the plurality of rotor cores 123 are alternately arranged one by one, the rotor 120 is provided with the same number of permanent magnets 124 and the rotor cores 123.

Each permanent magnet 124 has a first working surface 124a and a second working surface 124b. The magnetic force lines of the permanent magnet 124 are generated at the first working surface 124a and the second working surface 124b.

The first working surface 124a corresponds to the widest surface of the permanent magnet 124. The first working surface 124a faces the circumferential direction of the rotor 120. The first working surface 124a may be parallel to the radial direction of the rotor 120. The first working surface 124a faces the side surface of the body 123a in the circumferential direction of the rotor 120. The first working surface 124a is in surface contact with the side surface of the body 123a.

The second working surface 124b forms a boundary between the first working surface 124a and an obtuse angle. When the second working surface 124b forms the boundary between the first working surface 124a and the obtuse angle, the second working surface 124b is formed to be inclined in the radial direction of the rotor 120. When the direction away from the rotation axis is referred to as the inner direction of the rotor 120 in the direction toward the rotational axis, and the outer direction of the rotor 120, the second working surface 124b is compared to the first working surface 124a. ) Is formed in the outer direction.

When the first working surface 124a and the second working surface 124b form an obtuse boundary, corners are formed at the boundary between the first working surface 124a and the second working surface 124b. The edge is parallel to the axial direction of the axis of rotation.

When the first working surface 124a and the second working surface 124b form an obtuse boundary, the width of the permanent magnet 124 based on the circumferential direction of the rotor 120 is the first working surface 124a ) And gradually decreases from the boundary between the second working surface 124b to the outer end of the permanent magnet 124. The outer end of the permanent magnet 124 that is gradually narrowed by the second working surface 124b corresponds to the projection 123c that is gradually widened in the rotor core 123.

When the plurality of permanent magnets 124 are viewed from the inside of the rotor 120 based on the radial direction of the rotor 120, the plurality of permanent magnets 124 may include a plurality of rotor cores 123 and the rotor frame 121. It is covered by the inner column 121f. Then, when the plurality of permanent magnets 124 are viewed from the outside of the rotor 120, the plurality of permanent magnets 124 are covered by the outer wall 121e of the rotor frame 121. Here, the inside of the rotor 120 refers to a position where the bushing 122 is installed. And the outer side of the rotor 120 refers to a position corresponding to the opposite side of the bushing 122 in the radial direction with respect to the plurality of rotor cores 123 or the plurality of permanent magnets 124.

Each of the plurality of rotor cores 123 and the plurality of permanent magnets 124 includes first and second ends in a direction parallel to the axial direction of the rotation axis. Here, the first stage refers to the bottom of the plurality of rotor cores 123 and the bottom of the plurality of permanent magnets 124 based on the direction shown in FIG. 2. And the second stage refers to the top of the plurality of rotor cores 123 and the top of the plurality of permanent magnets 124.

However, in that the ordinal numbers 1 and 2 are booked to distinguish each other, the ordinal does not have any special meaning. Therefore, the upper ends of the plurality of rotor cores 123 and the upper ends of the plurality of permanent magnets 124 may be referred to as first stages. In addition. The lower end of the rotor core 123 and the lower ends of the plurality of permanent magnets 124 may be referred to as second stages.

The detailed structure of the rotor frame 121 will be described with reference to FIGS. 2 to 4.

The rotor frame 121 is connected to the rotating shaft through the bushing 122 installed in the bushing coupling part 121a at a position facing the center of the stator 110. The rotor frame 121 is formed to fix the plurality of rotor cores 123 and the plurality of permanent magnets 124. When a plurality of rotor cores and a plurality of permanent magnets 124 are put into a mold and the rotor frame 121 is formed, the rotor frame 121 may include the plurality of rotor cores 123 and the plurality of permanent magnets 124. It is integrated with.

Here, the meaning of integration means that one body is formed by insert injection, which will be described later. The assembly is formed by sequentially joining the parts together and can be dismantled in the reverse order of the joining. On the contrary, the integrated body has no concept of assembly or disassembly, so it is different from the assembly in that it is not dismantled unless it causes damage.

The rotor frame 121 is hollow as a whole and is formed in a cylindrical shape having any one bottom surface. The rotor frame 121 includes a bushing coupling portion 121a, a spoke 121b, a first stage base 121c, a second stage base 121d, an outer wall 121e, a plurality of inner pillars 121f, It includes a rotor frame pin (121g), a pin reinforcement rib (121h), a rotor frame hole (121i), a plurality of rotor core fixing jig hole (121j), and a plurality of permanent magnet fixing jig hole (121k).

The bushing coupling portion 121a and the spoke 121b have already been described with reference to FIG. 1 above.

The first end base 121c is formed in an annular shape to cover the first end of the plurality of rotor cores 123 and the first end of the plurality of permanent magnets 124. The first stage base 121c is formed around the outer periphery of the spoke 121b. The first end base 121c covers the first end of the plurality of rotor cores 123 and the first end of the plurality of permanent magnets 124 in a direction (lower side) parallel to the axial direction of the rotation axis. The first stage base 121c supports the first stage of the plurality of rotor cores 123 and the first stage of the plurality of permanent magnets 124.

The second end base 121d is formed in an annular shape to cover the second end of the plurality of rotor cores 123 and the second end of the plurality of permanent magnets 124. The second stage base 121d covers the second stage of the plurality of rotor cores 123 and the second stage of the plurality of permanent magnets 124 in a direction parallel to the axial direction of the rotation axis. The second stage base 121d supports the second stage of the plurality of rotor cores 123 and the second stage of the plurality of permanent magnets 124.

The first end base 121c and the second end base 121d are formed at positions spaced apart from each other in a direction parallel to the axial direction of the rotation axis. The first end base 121c and the second end base 121d are disposed to face each other in a direction parallel to the axial direction of the rotation axis. The movement of the plurality of rotor cores 123 and the movement of the plurality of permanent magnets 124 toward the direction parallel to the axial direction of the rotation axis is prevented by the first stage base 121c and the second stage base 121d.

The outer wall 121e is formed to surround the protrusions 123c of the plurality of rotor cores 123 and the outer ends of the plurality of permanent magnets 124 in the radial direction of the rotor 120. As will be described later, the rotor frame pin 121g is inserted into the rotor core slot 123e, and the outer wall 121e shows the outer sides of the rotor core 123 and the rotor frame pin 121g in the radial direction of the rotor 120. It is formed to wrap. For example, the outer wall 121e extends in a direction parallel to the axial direction of the rotation axis to connect the first end base 121c and the second end base 121d to each other, and the outer end and the second end of the first end base 121c It extends along the outer end of the base (121d).

The outer wall 121e is formed on the outermost portion of the rotor frame 121. Therefore, the plurality of rotor cores 123 and the plurality of permanent magnets 124 are all covered by the outer wall 121e outside the rotor 120.

The plurality of inner pillars 121f extend in a direction parallel to the axial direction of the rotation axis so as to connect the inner ends of the first end base 121c and the inner ends of the second end base 121d to each other. Here, the inner end refers to a circumferential portion corresponding to the inner diameter of the rotor frame 121.

The plurality of inner pillars 121f are formed at positions spaced apart from each other along the circumferential direction of the rotor frame 121. Here, the circumferential direction of the rotor frame 121 refers to the circumferential direction of the inner end of the first end base 121c and / or the circumferential direction of the inner end of the second end base 121d.

Since the plurality of inner pillars 121f are spaced from each other, the openings O for each of the regions defined by the inner ends of the first stage base 121c, the inner ends of the second stage base 121d, and the inner pillars 121f Is formed.

The inner ends of the plurality of rotor cores 123 are exposed in the radial direction of the rotor 120 through the opening O. The inner end of the rotor core 123 refers to the inner end of the body 123a. The inner end of the rotor core 123 exposed in the radial direction of the rotor 120 faces the stator 110.

Referring to FIG. 2, a plurality of rotor cores 123 and a plurality of inner pillars 121f are alternately formed one by one along the circumferential direction of the first frame 121. In addition, the plurality of permanent magnets 124 are covered by the plurality of rotor cores 123 and the plurality of inner pillars 121f in the radial direction of the first frame 121.

The head 123b of each rotor core 123 and each inner pillar 121f are in surface contact in a direction inclined with respect to the radial direction of the rotor frame 121. Therefore, the plurality of inner pillars 121f support the plurality of rotor cores 123 in the radial direction. And the movement of the plurality of rotor cores 123 toward the inside of the rotor frame 121 (toward the rotation axis) is prevented by the plurality of inner pillars 121f.

The plurality of rotor frame pins 121g protrude from the first end base 121c toward the second end base 121d. The plurality of rotor frame pins 121g extend along a direction parallel to the axial direction of the rotation axis. In some cases, a plurality of rotor frame pins 121g may protrude from the second stage base 121d toward the first stage base 121c.

The plurality of rotor frame pins 121g is formed between the inner end of the first end base 121c and the outer wall 121e in the radial direction of the rotor frame 121. In addition, the plurality of rotor frame pins 121g may be formed at positions spaced apart from each other along the circumferential direction of the rotor frame 121. It is also possible that two or more rotor frame pins 121g are formed in the same radial direction.

When two or more rotor frame pins 121g are formed in the same radial direction, one is formed at a position relatively away from the outer wall 121e, and the other is formed at a position relatively close to the outer wall 121e. The rotor frame pin 121g formed at a position relatively away from the outer wall 121e is inserted into the hole 123d of the rotor core 123.

A pin reinforcement rib 121h for reinforcing the connection strength with the outer wall 121e may be formed around the rotor frame pin 121g formed relatively close to the outer wall 121e in the same radial direction. The pin reinforcement ribs 121h may be formed on both sides of each rotor frame pin 121g. The pin reinforcement rib 121h is formed to connect the rotor frame pin 121g and the outer wall 121e. The pin reinforcement rib 121h may have the same height as the rotor frame pin 121g in a direction parallel to the axial direction of the rotation axis. The rotor frame pin 121g formed relatively close to the outer wall 121e and the pin reinforcement ribs around it are inserted into the rotor core slot 123e of the rotor core.

When the outer ring 125 to be described later is formed inside the outer wall 121e, the pin reinforcement rib 121h is connected to the outer wall along the axial direction of the rotating shaft. If the outer ring 125 is in close contact with the outer end of the rotor core 123, the pin reinforcement rib 121h may be connected to the outer wall 121e through the first end base 121c.

When the rotor frame 121 is formed by insert injection, a rotor frame pin 121g and a pin reinforcement rib 121h are formed in an area filled with molten injection raw material. Therefore, the rotor frame pin 121g formed at a position relatively away from the outer wall 121e has a shape corresponding to the hole 123d of the rotor core 123. In addition, the rotor frame pin 121g formed relatively close to the outer wall 121e and the pin reinforcement ribs 121h around it have a shape corresponding to the rotor core slot 123e.

The rotor frame hole 121i is formed at a position facing the rotor frame 121 along a direction parallel to the axial direction of the rotation axis. When the rotor frame pin 121g is formed in the first end base 121c, the rotor frame hole 121i is formed in the second end base 121d. Conversely, when the rotor frame pin 121g is formed in the second end base 121d, the rotor frame hole 121i is formed in the first end base 121c.

The rotor frame hole 121i is a seat where a mold pin was originally placed during injection molding for the manufacture of the rotor 120. Even if the molten raw material for insert injection is filled in the mold, the molten injection raw material is filled only above or below the mold pin, and the molten injection raw material cannot exist at the position where the mold pin is present. Therefore, as a result of insert injection, the rotor frame pin 121g and the pin reinforcing ribs remain in the area where the molten injection material is present, and the rotor frame hole 121i remains in the area where the mold pin was present.

When the insert injection complete rotor 120 is separated from the mold, the rotor 120 is released from the mold pin. It can be understood that the distance between the rotor frame pin 121g and the rotor frame hole 121i corresponds to the length of the mold pin. And it can be understood that the sum of the length of the mold pin and the length of the rotor frame pin 121g is a distance between the first end base 121c and the second end base 121d. Therefore, the length of the rotor frame pin 121g in the direction parallel to the axial direction of the rotation axis is shorter than the distance between the first end base 121c and the second end base 121d.

The plurality of rotor core fixing jig holes 121j may be formed in any one of the first end base 121c and the second end base 121d. The plurality of rotor core fixing jig holes 121j may be formed along the circumference between the outer wall 121e and the inner column 121f. The plurality of rotor core fixing jig holes 121j are formed at positions spaced apart from each other.

A rotor core fixing jig for fixing a plurality of rotor cores 123 may be formed in a mold for manufacturing the rotor 120. The rotor core fixing jig adheres the respective rotor cores 123 mounted on the mold pins to the mold pins in a direction parallel to the axial direction of the rotating shaft. Therefore, each rotor core 123 can be fixed along this direction.

Even if the molten raw material for insert injection is filled in the mold, the molten raw material cannot exist at the position where the rotor core fixing jig is present. Therefore, as a result of insert injection, the rotor core fixing jig hole 121j remains.

The permanent magnet fixing jig hole 121k is formed at the boundary between the first end base 121c and the inner column 121f, or is formed at the boundary between the second end base 121d and the inner column 121f. The permanent magnet fixing jig hole 121k is formed at each position corresponding to each permanent magnet 124 in the radial direction of the rotor frame 121.

A permanent magnet fixing jig for fixing a plurality of permanent magnets 124 may be formed in a mold for manufacturing the rotor 120. The permanent magnet fixing jig adheres each of the permanent magnets 124 mounted on the mold pin to the mold pin along a direction parallel to the axial direction of the rotating shaft. Therefore, each permanent magnet 124 can be fixed along this direction.

Even if the molten raw material for insert injection is filled in the mold, the molten raw material cannot exist in the position where the permanent magnet fixing jig is present. Therefore, as a result of insert injection, a permanent magnet fixing jig hole 121k remains. Since the permanent magnet 124 is visually exposed through the permanent magnet fixing jig hole 121k, the position of the permanent magnet 124 is visually confirmed from the outside of the rotor frame 121 through the permanent magnet fixing jig hole 121k. Can be.

When the head 123b is formed on the rotor core 123, inclination of the permanent magnet 124 in the mold toward the rotational axis direction can be prevented. Therefore, the permanent magnet fixing jig hole 121k is not formed at the boundary between the first end base 121c and the outer wall 121e or the second end base 121d and the outer wall 121e.

Meanwhile, the outer ring 125 is formed to surround the outer ends of the plurality of rotor cores 123 and the outer ends of the plurality of permanent magnets 124. The outer ring 125 is formed in an annular shape along the circumferential direction of the rotor 120 and has a constant length (height) along a direction parallel to the axial direction of the rotating shaft. The length (height) of the outer ring 125 may be constant along the circumference.

The outer ring 125 may be disposed to be in close contact with the outer ends of the plurality of permanent magnets 124 and the outer ends of the plurality of rotor cores 123. The outer end of the rotor core 123 refers to the outer end of the projection 123c. In this case, the outer wall 121e of the rotor frame 121 surrounds the outer ring 125. Figure 2 shows this structure.

The rotor frame 121 includes a plurality of rotor cores 123, a plurality of permanent magnets 124, and a plurality of rotor cores 123, a plurality of permanent magnets 124, and an outer ring to integrate the outer ring 125. Fix (125). The rotor frame 121 is formed to constrain the plurality of rotor cores 123, the plurality of permanent magnets 124, and the outer ring 125 in the axial and radial directions.

For example, the first end base 121c of the rotor frame 121 is the first end of the plurality of rotor cores 123 in the direction parallel to the axial direction (height direction), the first end of the plurality of permanent magnets 124 and Wrap the first end of the outer ring (125). The second stage base 121d wraps the second stage of the plurality of rotor cores 123, the second stage of the plurality of permanent magnets 124, and the second stage of the outer ring 125 in a direction parallel to the axial direction. . If it is based on the height direction as shown in the drawing, each of the first stage may be understood as the concept of the bottom and the top of the second stage. Accordingly, the plurality of rotor cores 123, the plurality of permanent magnets 124, and the outer ring 125 are fixed in a direction parallel to the axial direction of the rotating shaft.

In addition, the outer wall 121e of the rotor frame 121 is the outer end of the plurality of rotor cores 123, the outer end of the plurality of permanent magnets 124, and the outer ring 125 in the radial direction of the rotor 120. Wrap the hem. Accordingly, the plurality of rotor cores 123, the plurality of permanent magnets 124, and the outer ring 125 are fixed in the radial direction of the rotor frame 121.

When the outer ring 125 that is integrated with other elements of the rotor 120 is introduced by the rotor frame 121, the structural strength of the rotor frame 121 and further increases the structural strength of the motor 100 To increase the safety factor for rotational stiffness.

The rotor core 123, which is formed by stacking a plurality of sheets of electrical steel along the axial direction, concentrates the magnetic flux generated by the permanent magnet 124 to suppress leakage of the magnetic flux. If the outer ring 125 in close contact with the outer ends of the plurality of rotor cores 123 is formed of a magnetic material, the magnetic flux leaks to the outer ring 125. In this regard, the outer ring 125 should be formed of a non-magnetic material (non-magnetic substance, non-magnetic material).

The magnetic field characteristic of the motor 100 is affected by a relative permeability value. The non-permeability of the non-magnetic material is close to 1, and the non-permeability of the magnetic material is a value greater than 1. In the present invention, it is preferable that the relative permeability of the outer ring 125 is 1 to 1.05. When the relative permeability of the outer ring 125 is 1.05 or less, there is no change in the magnetic field characteristics of the motor 100, and even when the outer ring 125 is introduced, the performance of the motor 100 does not decrease.

In addition, in order to increase the structural strength of the rotor frame 121, it is preferable that the outer ring 125 has a tensile strength of 600 MPa or more. More preferably, the outer ring 125 may have a tensile strength of 700 MPa. Whether the structural strength of the rotor frame 121 is increased can be determined through the concept of a safety factor, and the safety factor is proportional to the tensile strength. Therefore, the greater the tensile strength of the outer ring 125, the higher the safety factor. A more detailed description of the safety factor will be described later.

Several types of stainless steel have a specific permeability of about 1.02. In addition, there are various types of stainless steel having a tensile strength of 600 MPa or more, and even 700 MPa or more. Therefore, if a type that satisfies the specific permeability condition and the tensile strength condition is selected from among stainless steels, and among them, an excellent economic and productivity type is selected, the selected type of stainless steel is used as a material for the outer ring 125. Can be.

Next, the size of the outer ring 125 will be described with reference to FIG. 5.

5 is a cross-sectional view of the portion V shown in FIG. 2.

The outer ring 125 is formed in an annular shape to surround the plurality of rotor cores 123 and the plurality of permanent magnets 124 in the radial direction of the rotor frame 121. The outer ring 125 is disposed between the plurality of rotor cores 123 and the rotor frame 121 in the radial direction of the rotor frame 121. In particular, in that the outer wall 121e of the rotor frame 121 surrounds the outer ring 125, the outer ring 125 is disposed between the plurality of rotor cores 123 and the outer wall 121e. In addition, the outer ring 125 is disposed between the plurality of permanent magnets 124 and the rotor frame 121 in the radial direction of the rotor frame 121.

However, the position of the outer ring 125 is not necessarily limited to this position, for example, the outer ring 125 may be disposed inside the outer wall 121e or may be disposed at a position surrounding the outer wall 121e. In this case, the inner circumferential surface of the outer wall 121e is in close contact with the outer ends of the plurality of rotor cores 123 and the outer ends of the plurality of permanent magnets 124.

The size of the outer ring 125 may be described as a thickness t based on the radial direction of the rotor frame 121 and a length h based on a direction parallel to the axial direction (up and down direction in FIG. 5). have.

The thickness t of the outer ring 125 is preferably 0.5 mm to 3.5 mm. If the thickness t of the outer ring 125 is smaller than 0.5 mm, the effect of supplementing the structural strength by the outer ring 125 is insufficient. Conversely, when the thickness t of the outer ring 125 exceeds 3.5 mm, the size of the rotor frame 121 and the size of the motor 100 are increased due to the excessive thickness. Furthermore, the outer ring 125 is formed by rolling a belt having a first stage 125a and a second stage 125b in an annular shape, as will be described later in FIGS. 7A and 7B, and the thickness t of the outer ring 125 ) Exceeds 3.5mm, which causes difficulties in manufacturing.

Since the present invention aims to have no effect on the original performance of the motor 100 even if the outer ring 125 is introduced, it is not desirable to increase the size of the motor 100 due to the outer ring 125.

On the other hand, the ratio (h / A) of the length (h) of the outer ring 125 and the length (A) of the rotor core 123 in the direction parallel to the axial direction of the rotating shaft is 0.3 to 1.5.

If the ratio (h / A) is less than 0.3, it means that the length of the outer ring 125 is shorter than the length of the rotor core 123 in a direction parallel to the axial direction of the rotation axis, and the outer ring 125 The effect of compensating the structural strength of the rotor 120 due to it is insufficient.

Conversely, when the ratio (h / A) exceeds 1.5, it means that the length of the outer ring 125 is excessively long compared to the rotor core 123. In this case, the size of the rotor frame 121 and the size of the motor 100 may increase unnecessarily.

More preferably, the ratio (h / A) of the length (h) of the outer ring 125 and the length (A) of the rotor core 123 is 0.66 to 1. The structural strength reinforcement effect (safety factor) of the rotor 120 by the outer ring 125 is linearly proportional to the ratio (h / A), but the slope of the graph showing the proportional relationship is reduced to 0.66 as a boundary. Therefore, in the range of less than 0.66, the effect of reinforcing the structural strength of the rotor 120 by the outer ring 125 is relatively large, and in the range of 0.66 or more, the effect of reinforcing the structural strength of the rotor 120 by the outer ring 125 is relatively large. small. In this respect, the ratio (h / A) is preferably at least 0.66.

When the ratio (h / A) of the length (h) of the outer ring 125 and the length (A) of the rotor core 123 is 1, the length (h) of the outer ring 125 and the length of the rotor core 123 It means that (A) is the same. If the rotor frame 121 in the absence of the outer ring 125 is compared with the rotor frame 121 in the case where the outer ring 125 is present, the axis of the rotation axis starts from the moment the ratio (h / A) exceeds 1 The length of the outer wall 121e starts to increase along the direction parallel to the direction. Therefore, in order to maintain the length of the outer wall 121e even when the outer ring 125 is introduced, it is preferable that the ratio (h / A) is at most 1.

Meanwhile, damage applied to the rotor frame 121 when the rotating shaft of the motor 100 rotates may be analyzed based on the safety factor. If the safety factor increases due to the introduction of the outer ring 125, it means that the damage applied to the rotor frame 121 is small.

The safety factor can be defined as the ratio (B / C) of the tensile strength (B) and the stress (C) applied to the rotor frame 121 when the motor 100 is operated. If the tensile strength of the rotor frame 121 is large, the safety factor is large, and if the stress applied to the rotor frame 121 is large, the safety factor is small. As a result of experimentally analyzing the result of introducing the outer ring 125 proposed in the present invention in comparison with the conventional structure without the outer ring 125, the safety factor of the rotor frame 121 has risen dramatically up to 4 times or more. And, despite the introduction of the outer ring 125, the original performance of the motor 100 was not affected.

Meanwhile, the plurality of rotor cores 123, the plurality of permanent magnets 124, and the outer ring 125 are integrated with the rotor frame 121 by insert injection. This process will be described with reference to FIG. 6.

6 is a perspective view showing the position and engagement state of the rotor core 123, the permanent magnet 124, the outer ring 125, and the bushing 122 before insert injection.

Injection molding is a method of molding a resin, and refers to a method of manufacturing a molded article having a shape corresponding to a mold by cooling and solidifying the molten raw material at a high pressure in a mold. Molded products produced by injection are called injection products.

Insert injection refers to a method of manufacturing a molded product by inserting an insert into a mold together with molten raw materials. The injection material has a shape corresponding to the mold, and the insert is manufactured inside the injection material while being integrated with the injection material.

Before insert injection, the plurality of rotor cores 123 and the plurality of permanent magnets 124 are alternately arranged one by one along the inner surface of the outer ring 125 in the mold. More specifically, a plurality of rotor cores 123 are arranged to be spaced apart from each other along a fixed circumference at a predetermined position of the mold. And permanent magnets 124 are arranged one by one between the two rotor cores 123.

The outer ring 125 is press-fit along the axial direction so as to be in close contact with the outer ends of the plurality of rotor cores 123 and the plurality of permanent magnets 124. In addition, the bushing 122 is disposed in the center of a region surrounded by a plurality of rotor cores 123 and a plurality of permanent magnets 124 in a mold.

When a plurality of rotor cores 123, a plurality of permanent magnets 124, an outer ring 125, and a bushing 122 are placed in the mold as described above, molten material is introduced into the mold, and insert injection is performed. , The rotor 120 shown in FIG. 2 is manufactured.

Next, the structure and manufacturing process of the outer ring 125 press-fitted to the outer ends of the plurality of rotor cores 123 and the outer ends of the plurality of permanent magnets 124 will be described with reference to FIGS. 7A and 7B. The manufacture of the outer ring 125 must precede insert injection.

7A is a conceptual diagram before connecting the first end 125a and the second end 125b of the outer ring 125. 7B is a conceptual diagram after connecting the first end 125a and the second end 125b of the outer ring 125.

The outer ring 125 is formed by rolling a belt having a first end 125a and a second end 125b in an annular shape. When the outer ring 125 is disposed inside the outer wall 121e of the rotor frame 121, the outer ring 125 includes the outer end of the plurality of rotor cores 123 and the plurality of permanent magnets 124. It is formed by rolling on the outer end. If the outer ring 125 is disposed outside the outer wall 121e of the rotor frame 121, the outer ring 125 is formed by rolling on the outer circumferential surface of the outer wall 121e.

The first end 125a and the second end 125b of the rolled outer ring 125 are welded to each other. Accordingly, a welding portion is formed between the first end 125a and the second end 125b of the outer ring 125.

The outer ring 125 may have a structure capable of compensating for physical bonding force by welding. For example, as illustrated in FIGS. 7A and 7B, the first stage 125a and the second stage 125b include circumferential protrusions 125a1 and 125b1 and crossing protrusions 125a2 and 125b2, respectively.

The circumferential protrusion 125a1 of the first stage 125a protrudes in the circumferential direction of the outer ring 125 toward the second stage 125b. In addition, the crossing protrusion 125a2 of the first stage 125a protrudes in the direction intersecting the circumferential direction of the outer ring 125 from the circumferential protrusion 125a1 of the first stage 125a. If the crossing direction is orthogonal to the circumferential direction, the crossing direction is a direction parallel to the axial direction of the rotation axis.

The circumferential protrusion 125b1 of the second end 125b protrudes in the circumferential direction of the outer ring 125 toward the first end 125a. In addition, the crossing protrusion 125b2 of the second end 125b protrudes in the direction intersecting the circumferential direction of the outer ring 125 from the circumferential protrusion 125b1 of the second end 125b. If the crossing direction is orthogonal to the circumferential direction, the crossing direction is a direction parallel to the axial direction of the rotation axis.

In order for the first end 125a and the second end 125b of the outer ring 125 to be coupled to each other, the first end 125a is formed to accommodate the second end 125b, or the second end 125b is It may be formed to accommodate the first stage (125a). For example, as illustrated in the drawing, only one circumferential protrusion 125a1 of the first stage 125a protrudes from the first stage 125a, while the circumferential protrusion 125b1 of the second stage 125b is the second stage. Two protrude from (125b). While the crossing protrusions 125a2 of the first stage 125a are formed on both sides toward opposite sides, the crossing protrusions 125bb2 of the second stage 125b are circumferential protrusions 125b1 of the second stage 125b ).

By this structure, the crossing protrusion 125a2 of the first end 125a and the crossing protrusion 125b2 of the second end 125b are staggered to each other. Accordingly, the first end 125a and the second end 125b may be constrained to each other in the circumferential direction of the outer ring 125. When the first ring 125a and the second ring 125b are pressed into the outer ends 125 of the plurality of rotor cores 123 and the outer ends of the plurality of permanent magnets 124, the inserts are injected. The primary preparation for conducting is completed. Thereafter, the rotor 120 is manufactured by insert injection described in FIG. 6.

8 is a conceptual diagram showing the flow of magnetic flux to explain the effect of the present invention.

The magnetic flux generated in the first working surface 124a and the second working surface 124b of the permanent magnet 124 must be concentrated by the rotor core 123 and flow toward the stator 110. However, if the outer ring 125 is formed of a magnetic material, the magnetic flux that should flow toward the stator 110 leaks out of the rotor 120, causing a decrease in motor performance. Therefore, it has been described above that the outer ring 125 should be formed of a non-magnetic material.

As a result of simulating the flow of the magnetic flux according to the configuration of the present invention, it was confirmed that the outer ring does not affect the flow of the magnetic flux as shown in FIG. 8. In particular, as long as the outer ring is formed of a non-magnetic material, it does not affect the flow of magnetic flux regardless of the detailed material, size, and location of the outer ring. Accordingly, when the outer ring 125 is introduced into the rotor, the structural strength of the rotor 120 may be improved without affecting the performance of the motor.

8, reference numeral 113 is a coil, 114 is a tooth, 123a is a body, 123b is a head, 123c is a protrusion, 123d is a hole, 123e is a rotor core slot, and 123f is a mac.

The motor described above is not limited to the configuration and method of the above-described embodiments, and the above-described embodiments may be configured by selectively combining all or part of each embodiment so that various modifications can be made.

Claims (15)

Stator; And
And a rotor rotatably disposed inside or outside the stator,
The rotor,
A plurality of rotor core segments arranged to be spaced apart from each other along the circumferential direction of the rotor on the inside or outside of the stator to form a plurality of permanent magnet placement slots;
A plurality of permanent magnets inserted one by one into the plurality of permanent magnet arrangement slots so as to be alternately arranged one by one with the plurality of rotor core segments along the circumferential direction of the rotor;
A rotor frame fixing the plurality of rotor core segments and the plurality of permanent magnets to integrate the plurality of rotor core segments and the plurality of permanent magnets; And
It is formed to surround the outer ends of the plurality of rotor core segments and the outer ends of the plurality of permanent magnets, and includes an outer ring made of a non-magnetic material,
The plurality of rotor core segments, the plurality of permanent magnets and the outer ring are integrally formed with the rotor frame by insert injection,
The outer ring is in close contact with the rotor frame, the motor characterized in that disposed between the plurality of rotor core segments and the rotor frame. According to claim 1,
The outer ring has a specific magnetic permeability of 1 to 1.05. According to claim 1,
The thickness of the outer ring based on the radial direction (radial direction) of the rotor frame, characterized in that 0.5mm to 3.5mm motor. According to claim 1,
The rotor frame is connected to the rotating shaft passing through the stator,
A motor characterized in that the ratio (h / A) of the length (h) of the outer ring and the length (A) of the plurality of rotor core segments in a direction parallel to the axial direction of the rotation axis is 0.3 to 1.5. The method of claim 4,
The rotor frame is connected to the rotating shaft passing through the stator,
A motor in which the ratio (h / A) of the length (h) of the outer ring and the length (A) of the plurality of rotor core segments in a direction parallel to the axial direction of the rotation axis is 0.66 to 1. According to claim 1,
The outer ring is a motor characterized in that the band having the first end and the second end is formed by rolling the outer ends of the plurality of rotor core segments and the outer ends of the plurality of permanent magnets. The method of claim 6,
The first stage and the second stage are characterized in that the motor is coupled to each other by welding. The method of claim 6,
Each of the first stage and the second stage,
A circumferential protrusion protruding toward the opposite end in the circumferential direction of the outer ring; And
And a cross-direction protruding part protruding in a direction crossing the circumferential direction from each circumferential protruding part. The method of claim 8,
The motor of claim 1, wherein the crossing projections of the first stage and the crossing projections of the second stage are staggered to each other. According to claim 1,
The outer ring is in close contact with the outer ends of the plurality of rotor core segments and the plurality of permanent magnets,
The rotor frame is a motor characterized in that it is formed to surround the outer ring. delete The method of claim 10,
The rotor frame is connected to a rotating shaft passing through an area enclosed by the stator,
The rotor frame is formed to cover the first end and the second end of the outer ring in a direction parallel to the axial direction of the rotating shaft. The method of claim 12,
The rotor frame is formed to cover first and second ends of the plurality of rotor core segments, and first and second ends of the plurality of permanent magnets in a direction parallel to the axial direction of the rotation axis,
The rotor frame,
A rotor frame pin inserted into a hole or a rotor core slot formed in each of the plurality of rotor core segments toward a direction parallel to the axial direction of the rotation axis; And
And a rotor frame hole formed at each position facing the rotor frame pin along a direction parallel to the axial direction of the rotation axis. According to claim 1,
The rotor frame is in close contact with the outer ends of the plurality of permanent magnets of the plurality of rotor core segments,
The outer ring is a motor characterized in that it is formed to surround the rotor frame. According to claim 1,
Each of the plurality of rotor core segments,
A body formed to face the permanent magnet in the circumferential direction of the rotor;
A head protruding from both sides along the circumferential direction of the rotor at the inner end of the body; And
Protruding from the outer end of the body, and includes a projection extending in two directions toward a direction away from each other to form a rotor core slot,
Each of the plurality of permanent magnet placement slots is formed by the body, the head and the projection of two rotor core segments disposed on both sides of the one permanent magnet based on any one of the plurality of permanent magnets. Motor.

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